dns-forwarding: T4578: Rewrite show dns forwarding

Rewrite op-mode "show dns forwarding statistics" to new format
Use vyos.opmode format

2 files changed, 96 insertions, 1 deletions

diff --git a/op-mode-definitions/dns-forwarding.xml.in b/op-mode-definitions/dns-forwarding.xml.in
index baf60efbd..5dea5b91b 100644
--- a/op-mode-definitions/dns-forwarding.xml.in
+++ b/op-mode-definitions/dns-forwarding.xml.in
@@ -74,7 +74,7 @@
                 <properties>
                   <help>Show DNS forwarding statistics</help>
                 </properties>
-                <command>sudo ${vyos_op_scripts_dir}/dns_forwarding_statistics.py</command>
+                <command>sudo ${vyos_op_scripts_dir}/dns.py show_forwarding_statistics</command>
               </leafNode>
             </children>
           </node>
diff --git a/src/op_mode/dns.py b/src/op_mode/dns.py
new file mode 100755
index 000000000..717652b9b
--- /dev/null
+++ b/src/op_mode/dns.py
@@ -0,0 +1,95 @@
+#!/usr/bin/env python3
+#
+# Copyright (C) 2022 VyOS maintainers and contributors
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License version 2 or later as
+# published by the Free Software Foundation.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+
+import sys
+
+from sys import exit
+from tabulate import tabulate
+
+from vyos.configquery import ConfigTreeQuery
+from vyos.util import cmd
+
+import vyos.opmode
+
+
+def _data_to_dict(data, sep="\t") -> dict:
+    """
+    Return dictionary from plain text
+    separated by tab
+
+    cache-entries	73
+    cache-hits	0
+    uptime	2148
+    user-msec	172
+
+    {
+      'cache-entries': '73',
+      'cache-hits': '0',
+      'uptime': '2148',
+      'user-msec': '172'
+    }
+    """
+    dictionary = {}
+    mylist = [line for line in data.split('\n')]
+
+    for line in mylist:
+        if sep in line:
+            key, value = line.split(sep)
+            dictionary[key] = value
+    return dictionary
+
+
+def _get_raw_forwarding_statistics() -> dict:
+    command = cmd('sudo /usr/bin/rec_control --socket-dir=/run/powerdns get-all')
+    data = _data_to_dict(command)
+    data['cache-size'] = "{0:.2f}".format( int(
+        cmd('sudo /usr/bin/rec_control --socket-dir=/run/powerdns get cache-bytes')) / 1024 )
+    return data
+
+
+def _get_formatted_forwarding_statistics(data):
+    cache_entries = data.get('cache-entries')
+    max_cache_entries = data.get('max-cache-entries')
+    cache_size = data.get('cache-size')
+    data_entries = [[cache_entries, max_cache_entries, f'{cache_size} kbytes']]
+    headers = ["Cache entries", "Max cache entries" , "Cache size"]
+    output = tabulate(data_entries, headers, numalign="left")
+    return output
+
+
+def show_forwarding_statistics(raw: bool):
+
+    config = ConfigTreeQuery()
+    if not config.exists('service dns forwarding'):
+        print("DNS forwarding is not configured")
+        exit(0)
+
+    dns_data = _get_raw_forwarding_statistics()
+    if raw:
+        return dns_data
+    else:
+        return _get_formatted_forwarding_statistics(dns_data)
+
+
+if __name__ == '__main__':
+    try:
+        res = vyos.opmode.run(sys.modules[__name__])
+        if res:
+            print(res)
+    except ValueError as e:
+        print(e)
+        sys.exit(1)